1. Field of the Invention
The present invention relates to drills, and more particularly to a drill having a support pin which is received in a pilot hole. This feature enables the drill to be pivoted somewhat as the blade bears against material being cut. The novel drill finds utility in applications wherein it is desirable to incline the drill while bearing down on the cutting blade. A principal contemplated use is in the field of dental anchors, wherein gum tissue must be cut away to install the anchor, and osteosurgery, wherein pins and other members must be inserted into bone tissue. However, the novel drill would be useful in many settings wherein the angle of the cut must be varied from that of the pilot hole. Illustratively, it may be necessary in repair and restoration work in fields other than dental and medical fields to accommodate localized areas of material which is not of sufficient strength and good condition to receive fasteners or otherwise support members being attached.
2. Description of the Prior Art
From time to time, it becomes necessary to install external members into a material which has deteriorated over time or with exposure to a deleterious influence. Frequently, localized conditions cannot be determined until the material is exposed by cutting. In the field of installing dental anchors in the jaw, the most advantageous angle at which the anchor is to be oriented may not be susceptible of being determined until actual drilling commences. If the dental practitioner drills a pilot hole, then he or she is constrained to the angle of the pilot hole. Should local conditions at the jaw require adjustment in drilling angle, then rigidity of the process threatens the quality of the remedial therapy.
A dental drill is shown in U.S. Pat. No. 4,787,848, issued to Stanley E. Ross on Nov. 29, 1988 having a circular cutting blade. There is no guide pin as seen in the present invention.
U.S. Pat. No. 5,098,293, issued to Lennart Loof et al. On Mar. 24, 1992, describes a machining device for implant work which device has a machining blade formed as a spherical member located at the end of a shaft. Although this configuration bears a superficial similarity to the preferred embodiment of the present invention, a significant difference exists in that the spherical member of the present invention is blunt and not capable of cutting. Also, the present invention has a circular blade located above the spherical member. By contrast, the spherical member of Loof et al. is the blade, and no annular blade is present in the device of Loof et al.
U.S. Pat. No. 1,216,683, issued to Edwin J. Greenfield on Feb. 20, 1917, describes a hole cutting saw intended for dental implants. The saw has an annular blade bearing teeth and has relief holes formed in the blade. There is neither a support pin projecting forwardly of the cutting edge of the blade, nor an enlarged blunt head located forwardly of the cutting blade, both being features of the present invention.
U.S. Pat. No. 1,333,388, issued to William E. Chester on Mar. 9, 1920, illustrates a dental drill having a fluted drill bit projecting ahead of an annular hole cutting blade. The fluted bit drills a pilot bore ahead of the hole cutting blade, but could not accommodate inclination of the hole cutting blade relative to the pilot hole as occurs in the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.